JPS6157609A - Fluorine-containing copolymer - Google Patents

Abstract

PURPOSE:The titled copolymer that is obtained by copolymerization of a specific composition of chlorotrifluroethylene, fatty acid vinyl ester and hydroxy group- containing allyl ether, thus being curable and suitable for use as a coating with good clarity, high tensile strength, and high shock resistance. CONSTITUTION:The objective copolymer is obtained by copolymerization of (A) 25-75mol% of chlorotrifluoroethylene, (B) 10-70mol% of a fatty acid vinyl ester of formula I [R1 is H, methyl; R2 is -CnH2n+1 (n is integer of 1-12)] such as vinyl acetate or a fatty acid isopropenyl ester, (C) 3-40mol% of a hydroxyl- containing allyl ether of formula II [R3 is -(CH2CH2O)m-H (m is 1-60 integer)] such as ethylene glycol monoallyl ether, as essential components, and additionallly (D) 0-20mol% of other monomers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to curable fluorine-containing copolymers, more specifically chlorotrifluoroethylene, fatty acid vinyl esters, fatty acid iso7°ropenyl esters, and hydroxy group-containing allyl ethers. The present invention relates to a curable fluorine-containing copolymer containing as an essential component.

(Industrial Application Fields) Fluorine-containing copolymers have traditionally been used as resins with excellent heat resistance, mechanical properties, chemical resistance, weather resistance, etc. Attempts to use fluorine-containing polymers as paints have been made in the past, starting with tetrafluoroethylene polymers and chlorotrifluoroethylene polymers, and more recently using vinylitene fluoride copolymers and other synthetic fluoropolymers. Modified fluororesin paints made by adding additives to resin paints are commercially available and are used primarily as coating materials that take advantage of their lubricity, non-stick properties, weather resistance, and chemical resistance in fields such as the chemical industry, food, architecture, and machinery. .

(Prior art) However, most of these paints are in the form of powder dispersed in water or special organic solvents, or in the form of powder itself, and both require baking at high temperatures. It is a highly skilled technique that can only be constructed by highly specialized engineers and manufacturers. On the other hand, solvent-based fluororesin paints have been attracting attention in recent years. These are hardening paints that have increased solubility in organic solvents and can be dissolved in common paint solvents.They can be applied on site in the same way as regular hydrocarbon-based solvent paints, and As a long-term maintenance-free paint that takes advantage of its weather resistance and chemical resistance, it is increasingly being used for construction, civil engineering, and mechanical metal applications.

In order to make a fluororesin soluble in organic solvents, it is necessary to disturb the crystallinity of the fluororesin and internally plasticize it (usually by a method such as copolymerization).

Furthermore, in order to use this as a paint, there are problems such as how to maintain the inherent rigidity of the resin, the molecular weight of the resin to adjust the viscosity of the paint, and the need to maintain chemical resistance and repaint. In order to form a film, it is necessary to introduce functional groups into the resin and cure it (a), which raises problems such as how to select the type and amount of functional groups, and cost issues.

Examples of attempts to solve the above-mentioned problems and apply fluororesins to solvent-based paints can be found in JP-A-57-34107 and JP-A-57-34108.

(Means for Solving the Problems) The present inventors have discovered that a copolymer of chlorotrifluoroethylene and fatty acid vinyl ester exhibits high transparency over a wide wavelength range, high tensile strength, and excellent impact resistance. British Patent No. 888,014 and V/
, H, TOMA8 etc. (J, Po1y+ner 5cie
nce, I 1(5), 455 (+953)), and has been attracting attention as a raw material for fluorine-containing paints for some time. However, the copolymer of chlorotrifluoroethylene and fatty acid vinyl ester alone produces a transparent, glossy, hard coating film, but has the disadvantage that overlapping coatings cannot be formed. Therefore, as a result of intensive research into copolymers with monomers that have functional groups that can cause curing reactions without impairing the physical properties mentioned above, we found that
A cy functional group is introduced into chlorotrifluoroethylene, fatty acid, nilnis til or fatty acid impropenyl ester by copolymerizing a hydroxy group-containing allyl ether, which is said to be difficult to radically copolymerize, with the above monomer. The present invention was achieved by successfully obtaining the desired curable copolymer.

The copolymer of the present invention is chloro l-IJ fluoroethylene,
The content of units based on fatty acid vinyl ester or fatty acid impropenyl ester, hydroxy group-containing allyl ether, and other comonomers is 25 to 75 mol%, 10 to 70 mol%, 3 to 40 mol%, and 0, respectively.
It is contained in a proportion of ~20 mol%, preferably 40-60 mol%, 20-50 mol%, 5-30 mol%, and 0~! It is in the range of 0 mol%.

The content of chlorotrifluoroethylene can be changed arbitrarily depending on the amount of each monomer in the preparation, but if it is too high, the copolymer will have poor solubility in organic solvents9, and production problems may occur. Problems arise in copolymer yield. On the other hand, if the amount is small, it is unfavorable from the viewpoint of physical properties such as weather resistance and chemical resistance.

Further, a copolymer having too high a fatty acid vinyl ester or fatty acid impropenyl ester content is unfavorable from the viewpoint of physical properties such as weather resistance and chemical resistance, and a copolymer having too low content leads to a decrease in molecular weight and is also unfavorable from the production standpoint. If the content of the hydroxy group-containing allyl ether is too high, the molecular weight will decrease and problems will also arise in terms of production.

On the other hand, if the content of the hydroxyl group-containing allyl ether is too low, the curing reaction is difficult to occur, resulting in a decrease in physical properties such as chemical resistance and weather resistance, and it becomes difficult to perform multiple coatings.

Furthermore, if the units based on other comonomers are too high, disadvantageous problems arise in terms of solubility, transparency and manufacturing.

The copolymer of the present invention is prepared using tetrahydrofuran (THF) at 30°C.
) has an intrinsic viscosity of 0.1 to 2.0 dl, /
? Preferably within the range of 0.2 to 0.5 dl/fi
It is important that '. If the intrinsic viscosity is too low, the physical properties of the coating film will deteriorate, workability will be deteriorated, etc. If the intrinsic viscosity is too high, the solubility in the solvent will decrease.

The copolymer of the present invention can also be used in combination with cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene and toluene, esters such as ethyl acetate and butyl acetate, nitrogen-containing solvents such as acetylacetamide and pyridine, 1, C1
, -trichloroethane, trichloroethylene, and other halogen-containing solvents. Furthermore, the solutions obtained by dissolving them in these solvents are colorless and transparent in all cases.

The copolymer containing chlorotrifluoroethylene, fatty acid vinyl ester or fatty acid impropenyl ester, hydroxy group-containing allyl ether, and other comonomers of the present invention can be prepared by solution polymerization in the presence of a radical initiator in a conventional manner. It can be obtained by copolymerizing the monomers by any method such as emulsion polymerization, suspension polymerization, or bulk polymerization.

Polymerization temperature in copolymer production -30~l Ofl'
C is preferably 0 to 70°C. Examples of the type of radical initiator include oil-soluble radical initiators such as diisopropyl peroxydicarbonate, tributyl peroxypinoclate, di-2-ethylhexyl(-oxydicarbohydrate), benzoyl peroxide, and lauroyl peroxide. Peroxides such as oxide, propionyl peroxide, trichloroacetyl peroxide, perfluorobutyryl peroxide, perfluorooctanoyl peroxide, azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, Alternatively, organic poron compounds such as triethylboron-oxygen or peroxide can be mentioned, and water-soluble initiators include hydrogen peroxide, potassium persulfate, ammonium persulfate, and redox initiators that combine these with metal salts, etc. It will be done.

The solvent is not particularly limited, but depending on the polymerization method, water, an ordinary organic hydrocarbon compound, a fluorine organic compound, or a combination thereof may be used. In the case of an aqueous system, a suspending agent or an emulsifying agent is usually used as a dispersion stabilizer.

Examples of fatty acid vinyl esters that can be used in the present invention include vinyl acetate, vinyl lactate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl isocaproate, vinyl bivarisucate, vinyl caprylate, etc., but the number of carbon atoms in the alkyl group is is preferably 1 to 3. Further, as the fatty acid impropenyl ester, there are impropenyl acetate, impropenyl propionate, etc., but impropenyl acetate is preferable from the viewpoint of production. As the hydroxy group-containing allyl ether, ethylene glycol monoallyl ether, diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, etc. can be used, but +C! HzC)ho→0 unit m is m=
Preferably, the number is 1 to 2. In addition to these essential components, other comonomers include esters of acrylic rR-t or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, methyl methacrylate, and glycidyl methacrylate, acrylamide, and N- Examples include acrylamides such as methylolac 1-noramide, and vinyl ethers such as ethyl vinyl ether and butyl vinyl ether.The purity of these comonomers must be <98% or more, as long as they do not contain impurities that do not interfere with normal radical polymerization. Gas chromatography purity is sufficient.

Since the copolymer thus obtained has active hydrogen in its molecular chain, it can be cured with a compound having a functional group that reacts with active hydrogen. That is, by adding polyvalent incyanates to a solution in which the present copolymer is dissolved in the above-mentioned solvent and scattering the solvent, the reaction proceeds at room temperature. By treating at a temperature higher than the temperature at which the polyvalent incyanate dissociates), the curing reaction proceeds and a cured coating film is obtained. It also reacts with melamine, urea resin, polybasic acids or their anhydrides at high temperatures to form a cured coating film. Furthermore, it is also possible to add pigments, ultraviolet absorbers, dispersion stabilizers, etc. to the solution of this copolymer, and in either case, good dispersibility is exhibited.

(Function) Since the copolymer of the present invention contains C7p bonds in its molecular chain, it has excellent weather resistance and chemical resistance, and since it contains an ester group, it is suitable for use with iron, aluminum, etc. In addition, since it contains active hydrogen, it can be cured by reacting with a compound having a functional group that reacts with active hydrogen. Moreover, the resulting coating film is transparent, hard, and glossy, so it can be used as a baking paint on iron, aluminum, etc. It can also be cured at room temperature, so it is also useful as a coating on concrete, wood, etc. be.

The present invention will be explained in detail below with reference to Examples.

Example 1 Hynyl acetate (VAc) 38.75', ethylene glycol monoallyl ether (BGMAE, >3
0.6 f, 645 ml of water, 75 ml of butyl alcohol (t-BuOa), methyl cell O-y
, (MO)0.15f, sodium borate '3. Of
, diinflobilbar oxydicarbohydrate (, TPP
) 0.75 f and purge the inside of the autoclave with nitrogen gas three times. The autoclave is then cooled by immersing it in a methanol-dry ice bath and degassed. Then chlorotrifluoroethylene (0'l'FE) 87.
5 P was introduced into the autoclave, and (CTF'E/V
Ac/'EGMA Fico 50/30/20 molar ratio) The temperature was gradually raised. After polymerization at 40°C for 24 hours, unreacted CTFI! : was removed, the autoclave was opened, the generated fine particles were filtered, washed with water, and dried. A copolymer was obtained.

The intrinsic viscosity of this copolymer measured in THF at 30°C is 0.
, 33 dl/S'. Furthermore, in the infrared absorption spectrum, there is a 10H group at 3.5307', 2,870-2
Absorption of c-H at ,990i' and c=o group at 1,760i' were observed.Also, DSI:!-TG
As a result of thermal analysis, no melting point was observed and it was found that weight loss due to TG begins at 250°C or higher.

This copolymer 402 was converted into methyl isobutyl ketone 905'
And toluene 50? Hexamethylene diisocyanate 2 (1, methyl in butyl ketone 40?, toluene 40f') was added to a solution dissolved in a mixed solvent of.

A solution containing 409 mixed solution of dibutyltin dilaurate 1.5 x 1(]''f was spread on a chromate-treated aluminum plate and a zinc phosphate-treated zinc iron plate to obtain a coating film. The iron plate used was one that had been degreased in advance.The physical properties of this coating film were measured using the same method as shown in Table 1. .

Table l Example 2 Contents with magnetic stirrer: il, 4JI autoclave with VAc now 3.0? , EiGMAK 5.1 f, t-
BuOH500sc/.

After charging 1.5 f of benzoyl peroxide (BPO) and polymerizing with nitrogen for 24 hours, unreacted 0TFK was purged, the autoclave was opened, and the contents were poured into a large amount of water to precipitate, filtered, and washed with water. , and dried to obtain copolymer 741. The intrinsic viscosity of this copolymer measured in THF at 30° C. was 0.24 d1/l. Further, as a result of elemental analysis, hydrogen was 4.49%, carbon was 40.70%, and chlorine was 13.70%. In the infrared absorption spectrum, 10H group at s, 53o;', c-H, '1.76 at 2,860-3.0007
Absorption of C=0 group was observed in 0♂.

This polymer 3? A coating solution obtained by adding 3.02 parts of a mixed solution of 0.51 parts of hexamethylene diisocyanate and 9.5 parts of ethyl acetate to a solution of 121 parts of ethyl acetate was applied to a degreased glass plate. The chemical resistance of the coating film is shown in Table 2. For comparison, C! TFK and VA
The chemical resistance of the coating film made of the copolymer containing only c is also shown.

However, in the table ◎: No change ○: Slight change observed
×: Example 5 showing dissolution Same as Example 1, content volume with magnetic stirrer “
1.41 stainless steel autoclave with VAc32.
39%KGMAI38.35', t-BuOH75me
1 MOo to water 645, 2F, sodium borate 3.
Or, lPP0.75S' was charged, and after nitrogen substitution, cooling solidification, and degassing, CTFE88.2 f'! i-Introduce (OTF'E/VAC/EGMAF= 50/2
5/25) The temperature was gradually raised. After polymerization was carried out at 40°C for 24 hours, unreacted CTFE'i was purged, and the product was filtered, washed with water, and dried to obtain copolymer 762. THF medium 3
The intrinsic viscosity measured at 0°C is 0.31 eL1/9. The elemental analysis of the copolymer shows 3.95% hydrogen and 37% carbon.
．． 83X chlorine was 0.65%.

Figure 1 shows the behavior of the relative elastic modulus and damping factor measured by the torsional free damping method after impregnating glass fibers with a coating solution obtained by preparing this copolymer in the same manner as in Example 1. (J-Ko 87213B Method) The results are shown in the graphs of the samples with and without the addition of the hardening agent. From this figure, the effect of hardening is clearly recognized.

In addition, 20 parts of this copolymer was added to 15 parts of methyl isobutyl ketone.
In a solution dissolved in a mixed solvent of toluene + 5S',
Titanium oxide (R-5N manufactured by Sakai Chemical Industries, Ltd.) +01 was added and kneaded in a hole mill for 1 hour. The resulting solution had good dispersibility and was able to form an attractive coating film.

Example 4 A stainless steel autoclave with an internal capacity of 1.4 and a magnetic stirrer, VAc 43.6 f, EGMAF! 5
．． +2, 700 tons of water & ammonium of perfluorooctanoic acid! 0. IP, sodium borate 0.
35 f, sodium dihydrogen phosphate 0.78 f, potassium persulfate! , charged with O2, replaced with nitrogen, cooled and solidified,
After degassing, CTFE58.6f was introduced into the autoclave, and (CT F]l!!/V Ac7'll!:GM
AE = 47/4815) The temperature was gradually raised.

After polymerization was carried out at 55° C. for 24 hours, unreacted cTFE was purged and the autoclave was opened. The produced latex was salted out with saturated saline, filtered, washed, and dried to obtain copolymer 752. The intrinsic viscosity measured in THF at 30°C is 1.56 dl/f, and the elemental analysis results are 5.00% hydrogen, 40.91% carbon, and 13.23% chlorine.
%Met.

The ultraviolet and visible spectra of the coating film obtained from this copolymer are shown in FIG. 2, and it can be seen that it transmits light well over a wide wavelength range.

Example 5 Isopropenyl acetate (PA) was placed in a stainless steel autoclave with an internal volume of 200 g and equipped with a magnetic stirrer.
E pull, 4AI 2. OF, 1.1.2-) Lichloro-1,2,2-trifluoroethane (Freon-1+3
)+oo Go, prepare BPOO132, nitrogen substitution, cooling solidification, deaeration, CTF Hu, 6! P was introduced into the autoclave, and (C'l'F11i':/PTPAe/1
! :GMAE==48/4715) The temperature was gradually raised.

Remember to carry out polymerization at 60°C for 24 hours. The obtained product was filtered, washed and dried to obtain a copolymer of 4.72.

The intrinsic viscosity of this copolymer measured in THF at 30°C is 0.
．． 35d1/f, and the infrared absorption spectrum of the copolymer contains 3, 10H group at 520 cm, and 2,950 N3.
Absorption of C-H and 1,740i'K O=O groups was observed in O1O♂, respectively.

This copolymer was dissolved in ethyl acetate in the same manner as in Example 1, and a hardening agent was added to form a coating film.
It became tack-free within a few hours, was completely cured after two days, and showed good chemical resistance.

Example 6 VAc 28.4 t, EGMAE5 in a stainless steel autocraneip with an internal volume of 1.41 and equipped with a magnetic stirrer
, I? s7 o y -I J 3500 x
ll, BPO 1.5t was charged, nitrogen purged, cooled and solidified,
After degassing, C! Introduced TFE 77.3 P, (OT
FVVA C/EGMAE = 64/3115) The temperature was gradually increased. After polymerization at 65°C for 24 hours, unreacted C
TFK was purged and treated as in Example 2 to obtain 251 copolymers. The intrinsic viscosity of this copolymer measured at 30°C in THF is 0.13 dl/P, and elemental analysis shows that hydrogen is 5.15% and carbon is 37.97%.
, chlorine was 13.47%.

When this copolymer 3f was dissolved in ethyl acetate + 2p and 5 parts of hexamethylenediyne rare based on the copolymer was added to the solution, a coating solution was applied to a degreased glass plate, and it became tack-free in 3 hours. It completely cured after two days. The resulting coating film was colorless and transparent, and the base grain test was 1.
It was 0 points.

Example 7 Vinyl propionate (VPr) 8.6?
, BGMAE 2.2 t% t-BuOH 15 ml, water 85 d, M60.02 y, sodium borate 0.45
? , n'Po, 1 I P, nitrogen substitution, cooling solidification, degassing>Tvv l 2 , s? (CTFE/VPr/KGMA)〉50/
40/I O) The temperature was gradually raised. After polymerizing at 40°C for 24 hours, the same procedure as in Example 1 was carried out to obtain +1.7 f'.
A copolymer was obtained. The intrinsic viscosity of this copolymer at 50°C in THF is 0.40 dl/f), and the infrared absorption spectrum contains 10H groups at 3,53 o, -, ;', 2,89
0~3,020Jmice-H11,750cm'c
Absorption of =o group was observed in each case. Also DS(!-
Thermal analysis by TG showed no melting point, and the onset of weight loss by TG was rare at 240°C. The results of elemental analysis were 4.19% hydrogen, 40.74% carbon, and 14.8% chlorine.

The obtained copolymer was dissolved in a solvent in the same manner as in Example 1, and 10 parts of inphorone diisocyanate was added as a hardening agent to the copolymer. The resulting coating solution was spread on a chromate-treated aluminum plate. The coating film obtained by
It showed good gloss and adhesion.

Example 8 Contents * 200 m stainless steel autoclave with VAc 12. with magnetic stirrer. Of, EGI MeAK
2.2ri.

After charging 3100 ml of fluorocarbon, BPOO, 3S', replacing with nitrogen, cooling and solidifying, and degassing, 6.3 r of CTFE was introduced, (CTT'B/VAQ/EGMAE=25/6
5/IO) The temperature was gradually raised.

Polymerization was carried out at 65°C for 24 hours. A copolymer of 8.2f was obtained by processing in the same manner as in Example 5. This polymer T
The intrinsic viscosity at 30° C. in HF was 0.25 dl/P. In addition, the results of elemental analysis showed 5.38% hydrogen and 4% carbon.
7,15.9 (, 6 points* with 7.64% chlorine.

The obtained copolymer was dissolved in a solvent in the same manner as in Example, and 10 parts of xylylene diincyanate was added as a hardening agent to the copolymer. The resulting coating solution was spread on a glass plate. The resulting coating showed good transparency and gloss.

Example 9 VAc 7.7 f, EGMAE 1.
＋? , hydroxyethyl acrylate (HEA) 0
．． 7f, Freon-113100d%BPOO, 3f was charged, nitrogen substitution, cooling solidification, degassing, 0TFE 12,
5 f was introduced, (C!TFFi/VA, C/EGMA
V1 (EA: 50/4215/3) The temperature was gradually increased. Polymerization was carried out at 65°C for 24 hours. The copolymer (1) and 22 were obtained in the same manner as in Example 5. The intrinsic viscosity of this copolymer measured in THF at 30°C is 0.22 dl/!
The results of elemental analysis were 3.82% hydrogen, 39.21% carbon, and 14.28% chlorine.

This copolymer was dissolved in a mixed solution of methyl isobutyl keto/toluene, melamine was added, and the mixture was heated at 160°C for 30 minutes.
When a minute curing reaction was carried out, a hard cured coating film was formed.

[Brief explanation of the drawing]

Figure 1 shows the behavior of the relative rigidity and attenuation rate of the fluorine-containing copolymer, and Figure 2 shows the light transmittance of the coating film. Figure 1 Figure 2 Light transmission of coating film Wavelength (πm)

Claims (3)

[Claims] (1) Chlorotrifluoroethylene and formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, R_1 = -H or -CH
_3, R_2=-C_nH_2_n_+_1, n=1~
fatty acid vinyl ester or fatty acid isopropenyl ester (an integer of 12) and the formula CH_2=CH-
CH_2-O-R_3 [However, R_3=-(CH_2C
A copolymer containing as an essential component a hydroxy group-containing allyl ether represented by H_2O)-_mH, m = an integer of 1 to 6], which contains chlorotrifluoroethylene, fatty acid vinyl ester or fatty acid isopropenyl ester, and hydroxy group-containing allyl ether. The content of units based on allyl ether and other comonomers is 25-75 mol% and 10%, respectively.
-70 mol%, 3-40 mol% and 0-20 mol% of the curable fluorine-containing copolymer. (2) The fluorine-containing copolymer according to claim 1, wherein the fatty acid vinyl ester is vinyl acetate or vinyl propionate. (3) The fluorine-containing copolymer according to claim 1, wherein the hydroxy group-containing allyl ether is ethylene glycol monoallyl ether.